Riffle pan



Feb. 19, 193s.

L. B. GOLDBERG ET AL RIFFLE PAN Filed March 26, 1954 grooves 18. The upper surface of the bottom above the inclined portion 12 is provided with a plurality of grooves 19 of substantially the same shape as the grooves 18 in the bottoms of the riiile grooves. A smooth section 20 extends from the upper end of the group of grooves 19 to the yupwardly extending flange 21. The riilie pan when in use, is preferably supported on a frame work erence numeral 22 designates a stationary frame member to the upper surface of which bearing blocks 23 are connected. Transversely extending. angle irons 24 rest on the bearing blocks of which there are two pair, as shown in Fig. 2. The transversely extending angle irons 24vare connect-,L ed by longitudinally extending angle `irons 25 `which serve to support the sheet metal supporting Y member 26 on which the riiile pan rests.

clined bottom portion l2 usually rests .on the top The inof the upper angle24 as shown in Fig. 1.

Whenthe riffle" pan isin-use, the frame on which itis supported is reciprocated transversely and the placer material and water are discharged onto thesmooth surface 20 and continues to iiow downwardly over the riiiles 19 and over the large riflle grooves 16 with their smaller rilTles 18 and the gangueis finally dischargedat the discharge end 9. Dueto the agitation and the flow of the placer material, the heavierparticles', such as gold, platinum and other heavy precious materials sink and iinally'become deposited in the rifes where-they are subjected to a gentle washing action by thev liquid which vflows through the riille'pan. Any large particles of valuable material are caught'in the rectangular riflie 14. After Ythe machine is operated for a certain length of form of the riflies, which, as above explained, are

of triangular shape and have their upper surfaces provided with a number. of spaced grooves or corrugations which preventthe iiow of therplacer material from carrying the gold and other previous metal lalong with the stream `as Ywould be the case if the upper surfaces of the riflie grooves were at and smooth. y Y

Due tothe inclination of the rifiie bottoms in the 'directionof pulp flow aucontinuous washing action is obtained that leaves the concentrate in-a richer condition than' can usually be obtained with riflies ofthe ordinary construction. Y

Since the riflle pan is subjected to transverse vibration, the inclined sides 7 and the vertical anges 8 serve to prevent the pulp from splashing over the'sides of the riiile pan during the time that the machine isin use.Y l u Y kIn machines having large '.capacity, the rife pan can be made in the form of an endless belt as shown in Fig.'5 where such a riie pan has been designated by reference numeral 27. This belt is supported on drums 28 and'29 and is'usually provided on'y its lower surface with a supportingY drum 30. A tank 31 is provided beneath the drum'29 and'this tank contains'water 32, whose level extends over the lower part of the riie pan where it bends around the drum 29. This rile pan is moved slowly in the direction'of thearrow and is therefore cleaned by passing through the water 32.v The bottom of the endless riilie pan is provided with grooves' 16 and with smaller grooves 18 the same as the riifle pan shown in Fig. 3.

- From the above'description it will be seen that the riffle pan which forms the subject of this invention is of a peculiar construction and its characteristic feature resided in the combination of large transversely extending ritle grooves' 16, whose supporting surfaces are provided with, parallelcan therefore be constructed at a very smalll cost .I

and will last longer than the usual metal pan, like that illustrated in Figs. 1 and 2 in which refrstbecause the rubber composition` is very resistant to wear, and second, vbecause it is not easily injured by rough handling. y

` Having described the invention what is claimed as newis:

1; An elongated rile pan having its sides turned Vupwardly 'so as@ to form flanges, the portion of the bottom between the flanges being provided with transversely extending grooves formed in v 7 the material of the'pan and whose upper Walls Vare substantially vertical and whose bottoms are v I Y 20 inclined in the direction of pulp ow, the bottoms of the grooves hawin'g'ftheir upper surfaces provided `with `longitudinaln parallel groovesg-]- 2. An elongated riiile pan of rubbencomposition, the edges of the riile pan being bent upwardf ly sov as to form anges,-the upper surface'of the bottom being'provided with transversely rex'-` tending groovesofsubstantiallytriangular cross section, the upper wall of the groove beingsbf stantially perpendicular to the planev f' the nboten tom of the rile box, the bottom-surface. of'each groovefbeing `inclined upwardly'in the direction of the-pulp flow, and provided with a plurality of parallel corrugations extending in the -direction of-the grooves. f

3. An elongated riflle pan ofrubber"composi-Y tion having its edges upwardly inclined sor as `to l form a trough-like structure having a transverse? ly latbottom and upwardly'V and outwardly inclined anges, the upper surface ofthe bottom and the inclined side flanges having Ya kplurality Vo1' parallel grooves extending transverselyfofgth rile pan and across aV portionof the upper faces of the anges, the upper'walls of the grooves.

beingsubstantially perpendicular toA thel of the bottom, the bottom surfaces of thegrooves' being upwardly inclined-in the'direction of pulp flow, the"bottor`n surface "of each groove being provided with a'plurality of parallel Ycorrugations o'f'substantially triangularfcrosssection.l

4. An elongated riiile pan of rubberyconposf.v tion having its edgesupwardly` and outwardly inv-- clined toform flangesQthe'bottom being Vtrans versely fiat, a portion of; thebottomfadjacent the receiving end being`inclined 'downwardly inthe direction of pulp flow1 fsaidinclined bottomrsur.- face being provided in its upperfsurface Vwith transversely extending grooves of substantially triangular cross section,v the bottomV surface bel tween the inclined bottomfportion-"and thejdischarge end of the riffle pan beingp rovideclwithy transversely extending Vgrooves -of substantially.

triangular cross section, the upper walls f the groovesbeing substantially yverticalV and the toms upwardly inclined in the' directionA o fp ulp 4 flow, the upper surfacesof 'the'inclined bottoms being provided with a plurality of small grooves f of substantially the same 'general cross sectional shape as the larger grooves. y f

5. A riflle pan inV accordance withY clairnl'kin which the groovesextend upwardly ,along-1 the'in"-A clined sides so asto terminate abovethelevel Y of the bottom of the 'riffle pan. 4 y i .W u w 6. A unitary riille panY of 1iexible rubber corn-` position and having'its sides upwardly andA outwardly -inclined so'as to form flanges, the bottonil being transversely at between the anges, the bottom having a plurality of transversely extending grooves of substantially triangular crosssection, the upper Wall of each'groove being sub- 5 stantially perpendicular and the bottom inclined upwardly in the direction of pulp 110W, the upper surface of the groove bottom having each a plurality of parallel longitudinally extending corrugation.

LOUIS B; GOLDBERG. NATHAN GOLDBERG. WILLIAM GOLDBERG. JACOB M. GOLDBERG. 

